1. Field of the Invention
The present invention is generally in the field of circuits and electrical modules. More particularly, the invention relates to electrical contacts for power modules.
2. Background Art
A contact for a power module may be exposed to significant stress, which can compromise the integrity of both the mechanical and electrical connection with the contact. The contact should be capable of withstanding harsh operating conditions, which often accompany the power module. For example, the power module may generate heat, which can reach the contact and the contact must often carry high current for the power module resulting in a high temperature in the contact. The high temperature is often accompanied by thermal cycling, compounding stresses imposed upon the contact. Furthermore, the power module may be deployed in an environment that introduces mechanical stress on the connection between the contact and the power module.
By way of example, the contact may conventionally comprise a bond wire or a lead affixed to a contact pad. The power module may be, for example, a motor drive inverter for a motor in a hybrid vehicle. The motor drive inverter may generate heat, which can reach the contact and the contact may carry high current for the motor drive inverter resulting in a high temperature in the contact. Furthermore, the motor drive inverter will frequently vacillate between periods of use and disuse, thereby exposing the contact to thermal cycling. Also, body rattle of the hybrid vehicle may cause mechanical stress on the connection of the contact. As such, conventionally there is a substantial risk of the contact failing due to, for example, bond wire lift off or solder wear out.
Thus, there is a need in the art for the capability to provide a power module with a contact while overcoming the drawbacks and deficiencies in the art.